scholarly journals Tyrosine Phosphorylation Modulates Peroxiredoxin-2 Activity in Normal and Diseased Red Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 206
Author(s):  
Alessandro Mattè ◽  
Enrica Federti ◽  
Elena Tibaldi ◽  
Maria Luisa Di Paolo ◽  
Giovanni Bisello ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Functional Characterization ◽  
Bioinformatic Analysis ◽  
Red Cells ◽  
Red Cell ◽  
The Novel ◽  
Peroxiredoxin 2 ◽  
Globally Distributed

Peroxiredoxin-2 (Prx2) is the third most abundant cytoplasmic protein in red blood cells. Prx2 belongs to a well-known family of antioxidants, the peroxiredoxins (Prxs), that are widely expressed in mammalian cells. Prx2 is a typical, homodimeric, 2-Cys Prx that uses two cysteine residues to accomplish the task of detoxifying a vast range of organic peroxides, H2O2, and peroxynitrite. Although progress has been made on functional characterization of Prx2, much still remains to be investigated on Prx2 post-translational changes. Here, we first show that Prx2 is Tyrosine (Tyr) phosphorylated by Syk in red cells exposed to oxidation induced by diamide. We identified Tyr-193 in both recombinant Prx2 and native Prx2 from red cells as a specific target of Syk. Bioinformatic analysis suggests that phosphorylation of Tyr-193 allows Prx2 conformational change that is more favorable for its peroxidase activity. Indeed, Syk-induced Tyr phosphorylation of Prx2 enhances in vitro Prx2 activity, but also contributes to Prx2 translocation to the membrane of red cells exposed to diamide. The biologic importance of Tyr-193 phospho-Prx2 is further supported by data on red cells from a mouse model of humanized sickle cell disease (SCD). SCD is globally distributed, hereditary red cell disorder, characterized by severe red cell oxidation due to the pathologic sickle hemoglobin. SCD red cells show Tyr-phosphorylated Prx2 bound to the membrane and increased Prx2 activity when compared to healthy erythrocytes. Collectively, our data highlight the novel link between redox related signaling and Prx2 function in normal and diseased red cells.

In vitro functional characterization of the novel DHH mutations p.(Asn337Lysfs*24) and p.(Glu212Lys) associated with gonadal dysgenesis

2018 ◽  
Vol 39 (12) ◽  
pp. 2097-2109 ◽  
Author(s):  
Asma Tajouri ◽  
Maher Kharrat ◽  
Syrine Hizem ◽  
Hajer Zaghdoudi ◽  
Ridha M'rad ◽  
...  
Keyword(s):  
Gonadal Dysgenesis ◽  
Functional Characterization ◽  
The Novel

Functional characterization of the novel breast tumor endothelial marker, SFRP2, on angiogenesis in the chick choriallantoic membrane and in vitro

2008 ◽  
Vol 207 (3) ◽  
pp. S98
Author(s):  
Andrew M. Courtwright ◽  
Shara Reihani ◽  
Eleanor G. Hilliard ◽  
David P. Ketelsen ◽  
Eric Olson ◽  
...  
Keyword(s):  
Breast Tumor ◽  
Functional Characterization ◽  
The Novel ◽  
Endothelial Marker

LACK OF EFFECT OF CORTICOSTEROIDS ON THE IN VIVO DISAPPEARANCE OF SULFHYDRYL-INHIBITED AND ANTIBODY-COATED ERYTHROCYTES

1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S28-S36
Author(s):  
Kailash N. Agarwal
Keyword(s):  
Red Cells ◽  
List Type ◽  
Red Cell

ABSTRACT Red cells were incubated in vitro with sulfhydryl inhibitors and Rhantibody with and without prior incubation with prednisolone-hemisuccinate. These erythrocytes were labelled with Cr51 and P32 and their disappearance in vivo after autotransfusion was measured. Prior incubation with prednisolone-hemisuccinate had no effect on the rate of red cell disappearance. The disappearance of the cells was shown to take place without appreciable intravascular destruction.

scholarly journals Functional identification of ygiP as a positive regulator of the ttdA-ttdB-ygjE operon

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2129-2135 ◽  
Author(s):  
Taku Oshima ◽  
Francis Biville
Keyword(s):  
Functional Characterization ◽  
Anaerobic Growth ◽  
Functional Identification ◽  
New Members ◽  
E Coli ◽  
Inner Membrane Protein ◽  
Tartrate Dehydratase

Functional characterization of unknown genes is currently a major task in biology. The search for gene function involves a combination of various in silico, in vitro and in vivo approaches. Available knowledge from the study of more than 21 LysR-type regulators in Escherichia coli has facilitated the classification of new members of the family. From sequence similarities and its location on the E. coli chromosome, it is suggested that ygiP encodes a lysR regulator controlling the expression of a neighbouring operon; this operon encodes the two subunits of tartrate dehydratase (TtdA, TtdB) and YgiE, an integral inner-membrane protein possibly involved in tartrate uptake. Expression of tartrate dehydratase, which converts tartrate to oxaloacetate, is required for anaerobic growth on glycerol as carbon source in the presence of tartrate. Here, it has been demonstrated that disruption of ygiP, ttdA or ygjE abolishes tartrate-dependent anaerobic growth on glycerol. It has also been shown that tartrate-dependent induction of the ttdA-ttdB-ygjE operon requires a functional YgiP.

scholarly journals Functional Characterization of the mazEF Toxin-Antitoxin System in the Pathogenic Bacterium Agrobacterium tumefaciens

2021 ◽  
Vol 9 (5) ◽  
pp. 1107
Author(s):  
Wonho Choi ◽  
Yoshihiro Yamaguchi ◽  
Ji-Young Park ◽  
Sang-Hyun Park ◽  
Hyeok-Won Lee ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Physiological Function ◽  
Functional Characterization ◽  
Site Directed Mutagenesis ◽  
In Vitro Assays ◽  
Cell Growth Inhibition ◽  
The Right

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.

scholarly journals Structural and Functional Characterization of SARS-CoV-2 RBD Domains Produced in Mammalian Cells

2021 ◽  
Author(s):  
Christoph Gstöttner ◽  
Tao Zhang ◽  
Anja Resemann ◽  
Sophia Ruben ◽  
Stuart Pengelley ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Functional Characterization

scholarly journals Characterization of a Cytotoxic Factor in Culture Filtrates of Serratia marcescens

2002 ◽  
Vol 70 (3) ◽  
pp. 1121-1128 ◽  
Author(s):  
Kent B. Marty ◽  
Christopher L. Williams ◽  
Linda J. Guynn ◽  
Michael J. Benedik ◽  
Steven R. Blanke
Keyword(s):  
Cytotoxic Activity ◽  
Serratia Marcescens ◽  
Mammalian Cells ◽  
Divalent Cations ◽  
Recombinant Expression ◽  
Cytotoxic Factor ◽  
Culture Filtrates ◽  
Type Strains

ABSTRACT Serratia marcescens culture filtrates have been reported to be cytotoxic to mammalian cells. Using biochemical and genetic approaches, we have identified a major source of this cytotoxic activity. Both heat and protease treatments abrogated the cytotoxicity of S. marcescens culture filtrates towards HeLa cells, suggesting the involvement of one or more protein factors. A screen for in vitro cytotoxic activity revealed that S. marcescens mutant strains that are deficient in production of a 56-kDa metalloprotease are significantly less cytotoxic to mammalian cells. Cytotoxicity was significantly reduced when culture filtrates prepared from wild-type strains were pretreated with either EDTA or 1,10-phenanthroline, which are potent inhibitors of the 56-kDa metalloprotease. Furthermore, cytotoxic activity was restored when the same culture filtrates were incubated with zinc divalent cations, which are essential for enzymatic activity of the 56-kDa metalloprotease. Finally, recombinant expression of the S. marcescens 56-kDa metalloprotease conferred a cytotoxic phenotype on the culture filtrates of a nonpathogenic Escherichia coli strain. Collectively, these data suggest that the 56-kDa metalloprotease contributes significantly to the in vitro cytotoxic activity commonly observed in S. marcescens culture filtrates.

scholarly journals Chemical Derivatization and Characterization of Novel Antitrypanosomals for African Trypanosomiasis

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4488
Author(s):  
Aboagye Kwarteng Dofuor ◽  
Temitayo Samson Ademolue ◽  
Cynthia Mmalebna Amisigo ◽  
Kwaku Kyeremeh ◽  
Theresa Manful Gwira
Keyword(s):  
Structural Modification ◽  
Spectroscopic Analysis ◽  
Microscopic Analysis ◽  
The Novel ◽  
Chemical Derivatization ◽  
African Trypanosomiasis ◽  
Chemical Structures ◽  
Normal Ratio

The search for novel antitrypanosomals and the investigation into their mode of action remain crucial due to the toxicity and resistance of commercially available antitrypanosomal drugs. In this study, two novel antitrypanosomals, tortodofuordioxamide (compound 2) and tortodofuorpyramide (compound 3), were chemically derived from the natural N-alkylamide tortozanthoxylamide (compound 1) through structural modification. The chemical structures of these compounds were confirmed through spectrometric and spectroscopic analysis, and their in vitro efficacy and possible mechanisms of action were, subsequently, investigated in Trypanosoma brucei (T. brucei), one of the causative species of African trypanosomiasis (AT). The novel compounds 2 and 3 displayed significant antitrypanosomal potencies in terms of half-maximal effective concentrations (EC50) and selectivity indices (SI) (compound 1, EC50 = 7.3 μM, SI = 29.5; compound 2, EC50 = 3.2 μM, SI = 91.3; compound 3, EC50 = 4.5 μM, SI = 69.9). Microscopic analysis indicated that at the EC50 values, the compounds resulted in the coiling and clumping of parasite subpopulations without significantly affecting the normal ratio of nuclei to kinetoplasts. In contrast to the animal antitrypanosomal drug diminazene, compounds 1, 2 and 3 exhibited antioxidant absorbance properties comparable to the standard antioxidant Trolox (Trolox, 0.11 A; diminazene, 0.50 A; compound 1, 0.10 A; compound 2, 0.09 A; compound 3, 0.11 A). The analysis of growth kinetics suggested that the compounds exhibited a relatively gradual but consistent growth inhibition of T. brucei at different concentrations. The results suggest that further pharmacological optimization of compounds 2 and 3 may facilitate their development into novel AT chemotherapy.

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